What is the Delta Ring on an AR?

[uneasy_rider]

I am looking at a two-piece Midwest industries free float tube that it says can be installed by cutting of the Delta Ring, but I am not sure what this is?

 

[rcmodel]

It's the wavy looking spring lock-washer, clip & cap that holds the handguard on at the receiver.

http://www.del-ton.com/AR_15_Delta_Ring_Assembly_p/bp1054.htm


rcmodel

 

[RockyMtnTactical]

On the handguards, on the side closer to the receiver, the delta ring and the weld spring apply pressure on the handguards keeping them in place.